Tube-drawing plug



Ma 3%,, mm, mmmm J. KEMP TUBE DRAWING PLUG Filed Jan. 20, 3.928

INVENTOR Jm@wwmfwmm atented 2%, WWW.

JOSEPH KEMP, 0F BTIMUHE, MARYLAND.

TUBE-DRAWING FLUW.

application filed January ac, 1928.

This invention relates to a tube drawing plug for copper, brass and soft metal tubing, and has for its object to provide, in a manner as hereinafter set forth, a plug of the class referred to so constructed and arranged to attain at all times a thoroughly efficient drawing of the tubing, to reduce breakage of the tubing to a minimum when the plug is forced to set position with respect to the tubing and die prior to the drawing of the tubing to provide a: grip between the plug and tubing when the plug is forced to initial position, and further obtaining a material saving in time, labor and material when the plug is employed, as the drawing operation is carried out with the reduction of spoilation ofthe tubing to a minimum.

Further objects of the invention are to provide, in a manner as hereinafter set forth, a tube drawing plug which is simple in its construction and arrangement, strong, unusually durable, compact, thoroughly efficient in its use, readily assembled, and comparatively inexpensive to manufacture.

With the foregoing and other objects in view the invention consists of the novel construction, combination and arrangement .of parts as hereinafter more specifically described, and illustrated in the accompanying drawings, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations and modifications can be'resorted to which fall within the scope of the claims hereunto appended.

In the drawings wherein like reference characters denote corresponding parts throughout the several views:

Figure 1 is a side elevation of a tube drawing plug, in accordance with this invention, showing the plug initially set with respect to a tubing and die, the tubing and die being shown in section.

Figure 2 is a View similar-. to Figure 1 with a portion of the tubing pulled or drawn illustrating the decreased diameter of the drawn tubing with respect to the remaining part thereof.

Figure 3 is a section on line 33 Figure 1.

Figure a is a side elevation of a modified Serial No. 24%,253.

form of tube drawing plug in accordance with this invention.

Figure 5 is an end View of the form shown in Figure 4:.

Figure 6 is an elevation of still another modified form of tube drawing plug in accordance with this invention.

Referring to the drawings in detail 1 indicates a die, which contacts with the exterior surface of a tubing 2 which is to be reduced in diameter and extended in the length in the well known operation of tube drawing. With reference to Figures 1, 2 and 3 the plug 'is generally indicated'at 3 and is carried by a rod a, the latter being so mounted as to be capable of retraction from the die. At the rear end of the rod a suitable means, not shown, is employed for gauging the precise position in which the plug 3 is inserted to coact with the die to provide for the required diameter of the tube when drawn.

With reference to Figures 1, 2 and 3 the plug comprises a slightly tapered body portion 5, and a nose 6 extended from the forward end of the body portion 5 and tapered. The nose 6 is of less length than the body portion 5. The rear end er the body portion 5 is beveled as at 7 and merges into a shank '8 which is welded to the rod 4:. The plug 3 is formed of hardened steel, but. has the forward part of its nose softened or malleable, whereby when the plug is initially positioned the softened forward part of the nose 6 will prevent breakage of the tube 2. At the point of joinder of the body portion 5 with the nose 6, a shoulder 9 is formed due to the inner end of the nose 6 being of less diameter than the forward end of the body portion 5. The taper of the body portion 5 from its rear to its forward end is very slight, preferably forty thousandths of an inch. The taper of the nose 6 from its rear to its forward end is approximately ten degrees. The head 3 is solid from end to end, that is to say solid from the rear end of the shank 8 to the forward end of the nose 6. The tapered nose 6 relieves the expansion or formlng action on the tube by the body portion 5.

The form of plug shown in Figure 4 and indicated generally at 10 is constructed in the same manner as the plug 3, with this exception that the nose 11 of the plug 10 is stepped as indicated at 12, but the nose 11 has the forward ortion thereof softened or malleable to er orm the same function as the softened forward portion of the nose 6. Otherwise than that as stated'the plug shown in Figure 4 is the same as that shown in Figure 1.

The form of plug shown in Figure 6 is the same as that shown in Figure 1, with this exception that the nose 13 of the plug 14 shown in Figure 6 is of uniform diameter throughout, but of less diameter than the diameter of a body portion 15 of the plug 14. Otherwise than that as stated the form of plug shown in Figure 6 is the same as that shown in Figures 1 and 4.

Preferably the nose 6 of the plug 3 is of greater length than the nost 13 of the plug 14, but the nose 11 of the plug 10 is of greater length than the nose of either of the plugs 3 or 14.

The noses provide a grip between the plug and the tube when the plug is initially set. The body portion of the plug provides a snug fit between the die and the tube and also for the desired diameter of the tubing when drawn. The ste s on the nose Ill correspond to the taper on t 1e nose 6.

The construction of the plugs will prevent their missin any tubing. lVhat is meant by missing 1s that the tube draws through the die, but the plug must be in the right position to catch before the tube will draw. The tubing will go in about two feet before it will catch.

The construction as set forth provides a metallic lug having the forward end of its nose ma leable and the remaining portion thereof hard. The setting up of the nose of the plug with a malleable forward end not only acts to prevent the breaking of the tubing when the plug is inserted, but further acts to reduce to a minimum the breaking or damaging of the plug when initially positioned, and therefore it is thought the many advantages of a tube drawing plug, in accordance with this invention can be readily understood, and although the preferred embodiment of the invention is as illustrated and described, yet it is to be understood that changes in the details of construction can be had which fall within the scope of the invention as claimed.

What I claim is:

1. A tube drawing plug formed of metallic material and including a tapered body portion and a gripping nose extended from the forward end of said body portion, said gripping nose having its forward end ossessing a malleable characteristic, the remalning porfliondof said nose and said body portion being 2. A tube drawin plug formed of metallic material and inclu ing a tapered body portion and a grippin nose extended from the forward end of said body portion, said gripping nose having its forward end possessing a malleable characteristic, the remaining portion of said nose and said body portion being hard, said nose of less diameter than the diameter of said body portion.

3. In combination, a tube drawing plug formed of metallic material and including a body portion provided at one end with a shank and at its other end with a nose having its outer end possessing a malleable characteristic, said shank and nose of less diameter than the diameter of said body portion, and a rod welded to said shank.

4. A tube drawin plug formed of metallic material and inclu ing a shank at one end for connection to a shifting rod therefore and further includin a gripping nose spaced from the shank and iaving its forward end possessing a malleable characteristic, said plug further including a body portion interposed between the nose and the shank and of greater diameter than the diameter of the shank and nose.

5. A tube drawing plug formed of metallic material and includin a shank at one end for connection to a shi ting rod therefor and JOSEPH KEMP. 

